Green cards serve as proof of an individual’s permanent legal residence in the U.S.

A senior administration official clarified on Saturday afternoon that green card holders from the seven countries affected in the order who are currently outside the U.S. will need a case-by-case waiver to return to the U.S.

Green card holders in the U.S. will have to meet with a consular officer before departing the country, the official said.

Trump signed an executive action Friday halting the country’s Syrian refugee resettlement program and halting all refugee resettlement for 120 days as well as imposing a 90-day ban on people from seven Muslim-majority countries.

The administration says the halt in the resettlement program is designed to give it time to tighten the vetting process for refugees. The order also gives Christian refugees priority in the resettlement process.

“If you were a Muslim you could come in, but if you were a Christian, it was almost impossible and the reason that was so unfair, everybody was persecuted in all fairness, but they were chopping off the heads of everybody but more so the Christians,” Trump said in an interview with Christian Broadcasting Network on Friday.

“And I thought it was very, very unfair,” he continued. “So we are going to help them.”

A Pew Research Center report found that the U.S. admitted nearly equal number of Muslim and Christian refugees in 2016.

As a candidate, Trump campaigned on a promise of cracking down on the country’s refugee program, arguing that terrorists could hide among refugees as a way of gaining entrance to the U.S.

At different points, he also called for a temporary ban on all Muslims entering the country and the creation of a Muslim registry.